The purpose of our research is to gain knowledge and develop techniques that will help in the provision of the orthomolecular, correct, amounts of essential nutrients in the diet of human beings such that they will be in optimum health. We are interested in the distribution function of human need for each of the essential nutrients in both the well and diseased states. We wish to measure these distribution functions and to be able to place each individual human being on these distribution functions in such a way as to advise him about adjustment in the molecular composition of his body fluids that may improve his health. The rationale for our work is summarized in the article Orthomolecular Psychiatry, Science 160, 265 (1968). We have developed experimental techniques based on loading with essential nutrients and on profile measurement and pattern recognition of urinary chromatograms for the purposes of producing faster, better, and cheaper methods of diagnosis and of following the course of diseases and the effectiveness of prophylactive and therapeutic measures. We have initiated investigations into the possibility that direct introduction of urine samples into various kinds of mass spectrometers may be superior to chromatography for this purpose. In this proposal, we request funds for a mass spectrometer in order to extend these studies of direct introduction of body fluids into the mass spectrometer. We also wish to use the mass spectrometer for the identification of substances in our chromatographic profiles and for various experiments on the metabolism of essential nutrients.